Control Joint Device

ABSTRACT

A control joint device including a reciprocating means, a surface breaking member and a ridge member having a generally flat bottom surface except for a first ridge along, at least, a portion of its length, wherein, in use, the first ridge of the ridge member is positioned behind the surface breaking member, the surface breaking member is mechanically reciprocatable in a straight line between a first position and a second position along an axis substantially perpendicular to the plane of a setting material, the first position being substantially level with the first ridge of the ridge member and the second position being spaced apart from the first position and wherein the ridge member further includes a planar surface from which the first ridge extends.

FIELD OF THE INVENTION

The present invention relates to a control joint device and, particularly but not exclusively, to a control joint device for concrete.

BACKGROUND

Concrete, and other materials which are at least partially liquid before setting, shrinks as it dries and hardens. The shrinkage creates tension within the concrete that can cause it crack. In addition, temperature changes and other pressures on the concrete can also create tension which can cause cracks. To avoid the cracks appearing randomly, control joints, which are grooves or lines, are created in the concrete. The control joint acts as pre-weakened stress points that encourage the concrete to crack at these locations. The control joints must be deep enough to perform their job. For example, as a guide, the depth of the joint should be around a quarter of the thickness of the slab.

Control joints are, typically, applied manually using a grooving trowel. This is a tool which has a generally flat bottom surface except of ridge down the centre. The ridge on the bottom surface of the trowel needs to be, at least, deep enough to encourage the tension cracks to occur at the control joint. A control joint can then be set into concrete by pushing the trowel into the concrete at a point during curing when the groove created by the ridge of the trowel will remain. As this means that the concrete is partly set, it can take a significant amount of effort during the manual application to create the groove.

SUMMARY OF THE INVENTION

According to the present invention there is provided a control joint device including a reciprocating means, a surface breaking member and a ridge member having a generally flat bottom surface except for a ridge along, at least, a portion of its length, wherein, in use, the ridge of the ridge member is positioned behind the surface breaking member, the surface breaking member is mechanically reciprocatable in a straight line between a first position and a second position along an axis substantially perpendicular to the plane of a setting material, the first position being substantially around level with the ridge of the ridge member and the second position being spaced apart from the first position, and wherein the ridge member further includes a planar surface from which the first ridge extends.

Preferably, the planar surface extends beyond the position of the surface breaking member and has a recess or hole through which the surface breaking member is reciprocatable.

Preferably, the surface breaking member has a second ridge.

Preferably, the second ridge curves upwards at a forward end of the surface breaking member.

Preferably, the second position is adjustable.

Preferably, the rate at which the surface breaking member is reciprocated is adjustable.

Preferably, the reciprocating means is a retrofitted jigsaw device.

According to another embodiment of the invention, the control joint device may be controlled remotely.

Preferably, the device is controlled wirelessly.

In yet another embodiment of the invention, the control joint device includes a track drive system.

Preferably, the track drive system is guided by at least one sensor or sensor system.

Preferably, the at least one sensor or sensor system includes a laser.

Preferably, the track drive system includes four wheels.

Aspects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the following drawings in which:

FIG. 1 illustrates a side view of a control joint device according to one embodiment of the invention;

FIG. 2A, 2B and 2C illustrates a top view, front view and side view of an control joint device according to one embodiment of the invention; and

FIG. 3A, 3B and 3C illustrates a perspective view, front view and side view according to one embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

As mentioned above, control joints in concrete, and any other materials in which a pre-defined joint at which a crack can occur, are, generally, applied manually using a grooving trowel by forcing a ridge on the bottom of the trowel into the concrete when it is partially cured. This leaves a groove made by the trowel and repeating movement of the trowel in the same direction creates the control joint. This manual job can be physically tasking and, in addition, slow to complete.

Referring now to FIG. 1, a control joint device 10 includes a reciprocating means 12, which in this example is an electric hand tool, the reciprocating means including a reciprocating member 14, a surface breaking member 16, attached to the reciprocating means 12 at the reciprocating member 14 and a ridge member 18. The ridge member 18 is attached to the reciprocating means 12 at a fixed, non-reciprocating, location. In this manner, the reciprocating means 12, when activated, reciprocates the surface breaking member 16 with respect to the ridge member 18 in along an axis A, which is substantially perpendicular t.

As can be see in FIG. 2A, 2B and 2C, the ridge member 18 has a generally planar surface 20, which has along at least part of its longitudinal axis a first ridge 22. In addition, the ridge member 18 has connection means 24 for connecting to the reciprocating means 12 and a recess 26, the recess 26 being generally along the same axis as the first ridge 22. The recess 26, when the ridge member 18 is connected to the reciprocating means 12, is for the surface breaking member 16 to reciprocate in close proximity and on substantially the same axis as the first ridge 22. The first ridge 22, in this example, is in the shape of a ‘V’, having a wider portion towards the planar surface 20 and a coming to a point away from the planar surface 20. The use of a ridge in this manner allows for a point of strain to occur and encourages a crack, or control joint, at this location. Other shapes which perform the same function would also be suitable for the first ridge 22. The planar surface 20 allows the control joint device 10 to travel along the surface of the material and smooths any ripples or holes caused by the action of the surface breaking member 16.

Referring now to FIG. 3A, 3B and 3C, which shows the surface breaking member 16 in more detail, has attachment means 30, for attaching to the reciprocating member 14, and a second ridge 32. In this example, the second ridge 32 extends along the bottom surface of the surface breaking member 16 and then through 90 degrees at the front of the member 16. As such, the second ridge 32 is shaped to gradually force material either side of the first ridge 22 as the device 10 is moved forward. The second ridge 32, in this example, is, like the first ridge 22, shaped in a ‘V’. The ‘V’ shape allows the surface breaking member 16 to more easily part the material and, as it corresponds with the first ridge 22, creates a smooth control joint.

In use, the device 10 is placed onto a setting material in which a control joint is desired. The reciprocating means 12 is then activated which moves the surface breaking member 16 between a first position and a second position along an axis A substantially perpendicular to the plane of the setting material. The first position is on or around the extent that the first ridge 22 extends perpendicularly from the plane of the planar surface 20 of the ridge member. The second position is spaced apart from the first position along the axis A away from the plane of the planar surface 20. The second position may be large enough, and the period of the reciprocal motion long enough such that the surface breaking member 16 has a hammer motion. Alternatively, the second position may be small enough, and the period of the reciprocal motion short enough such that the surface breaking member 16 has a vibrating motion. That is, both extremes of movement, and the alternative positions therebetween, are suitable to create a control joint with this device. The most appropriate choice of movement will depend on the material in which the control joint is being made.

Taking into account the variability in movement that may be desired above, the control joint device 10 preferably has a variable speed motor which enables the speed of the movement between the first position and second position to be adjusted. In addition, it is also preferable that the extent of travel of the surface breaking member 16 can be adjusted. That is, the placement of the second position along the axis A can be adjusted.

In one embodiment of the invention, the surface breaking member 16 and the ridge member 18 are retrofitted to a reciprocating tool such as a bayonet saw, also known as a jigsaw. The attachment means 32 of the surface breaking member 16 and connection means 24 of the ridge member 18 are preferable arranged so that they can be connected/attached to a jigsaw device or such similar reciprocating tool without modification.

In another embodiment of the invention, the control joint device may be controlled remotely, and may include that the device is controlled wirelessly. The controls may include the ability to turn the reciprocating action on or off as well as the ability to drive or steer the control joint device from one location to another.

Further, the control joint device may be driven on a track drive system. The track drive system could be guided by at least one sensor or sensor system to ensure that the control joint device performs efficiently and accurately. The track drive system may have a sensor or sensor system that includes a laser to guide the control joint device. The track drive system may have the ability to drive the control joint device to produce straight or curved control joints.

The track drive system can include a set of four wheels or is a four wheeled track system. Further, the reciprocating action may be driven off the wheel axle of the track drive system or may be driven off a separate drive motor.

The invention is not limited to the embodiments illustrated in the drawings but can be varied within the scope of the accompanying claims. 

1. A control joint device including a reciprocating means, a surface breaking member and a ridge member having a generally flat bottom surface except for a first ridge along, at least, a portion of its length, wherein, in use, the first ridge of the ridge member is positioned behind the surface breaking member, the surface breaking member is mechanically reciprocatable in a straight line between a first position and a second position along an axis substantially perpendicular to the plane of a setting material, the first position being substantially level with the first ridge of the ridge member and the second position being spaced apart from the first position and wherein the ridge member further includes a planar surface from which the first ridge extends.
 2. A device as claimed in claim 1, wherein the planar surface extends beyond the position of the surface breaking member and has a recess or hole through which the surface breaking member is reciprocatable.
 3. A device as claimed in claim 1, wherein the surface breaking member has a second ridge.
 4. A device as claimed in claim 3, wherein the second ridge curves upwards at a forward end of the surface breaking member.
 5. A device as claimed in claim 1, wherein the second position is adjustable.
 6. A device as claimed in claim 1, wherein the rate at which the surface breaking member is reciprocated is adjustable.
 7. A device as claimed in claim 1, wherein the reciprocating means is a retrofitted jigsaw device or other reciprocating tool device.
 8. A device as claimed in claim 1, wherein the device is controlled remotely.
 9. A device as claimed in claim 8, wherein the device is controlled wirelessly.
 10. A device as claimed in claim 8, wherein the power to the reciprocating action may be switched on or off.
 11. A device as claimed in claim 8, wherein the control joint device may be steered or driven from one location to another.
 12. A device as claimed in claim 8, wherein the device may be controlled to produce straight or curved control joints.
 13. A device as claimed in claim 8, wherein the control joint device includes a track drive system.
 14. A device as claimed in claim 13, wherein the track drive system is guided by at least one sensor or sensor system.
 15. A device as claimed in claim 14, wherein the at least one sensor or sensor system includes a laser.
 16. A device as claimed in claim 13, wherein the track drive system includes four wheels or is a four wheeled track drive system.
 17. A device as claimed in claim 13, wherein the reciprocating action may be driven off the wheel axle of the track drive system or may be driven off a separate motor. 